When winding continuously-fed tape or sheet material, e.g., paper, cloth or foil sheets, the problem is well known of exchanging a winding mandrel having a full roll of material for an empty winding mandrel without interrupting the supply.
Numerous machines have been provided in the past for solving this problem. A storage unit has been provided ro receive the material to be wound during the exchange operation. Such a storage unit has been provided by passing the incoming material around one or a plurality of compensating rollers and increasing the length of the path traveled by the incoming material by increasing the spacing between the compensating rollers, as shown, for example, in German Published Patent Application No. 21 51 829, FIG. 1, numeral 16. The disadvantage of such a storage unit lies in the requirement for a comparatively expensive additional compensating roller device.
It is also known, however, to carry out the exchange of winding mandrels without having an additional storage means. In a well-known device, the winding operation from a fixed roller onto a new winding mandrel which, in turn, lies against a drum, is conducted by carrying the sheet material over a sheet deflecting device shown, for example, in German Published Patent Application No. 27 05 776. This sheet deflecting device comprises a deflecting element which extends over the whole width of the sheet or tape and which is movable between the drum and the fixed roller, thereby deflecting the sheet by establishing a curve of the sheet. The disadvantage of this well-known device, and also the disadvantage of a similar device as described German Accepted Patent Application No. 21 29 410, is that after cutting the continuously-fed sheet material to form the end of the material on a full roll and the subsequent starting end of the material to start a new roll to be wound, there is insufficient distance to allow the usual and static-free transport of the full roll from the winding station.
To overcome this disadvantage, a device for winding long sheet or tape sections has been proposed in which a contact band is located above a conveyor belt by a distance corresponding to the diameter of the roll of material, said contact band running against the direction of movement of the conveyor belt (German Pat. No. 20 02 725). The additional conveyor belt is, however, a comparatively expensive and complicated device.
Another winding machine is known from German Accepted Patent Application No. 19 48 453 in which, after having completed the winding of a full roll and after having cut the sheet material, deterioration in the tight winding by loosening of the roll is prevented. In this machine, rails are provided which are guided by rack-and-pinion gear means.
Still another machine for the continuous winding of moving tapes in known which has a plurality of roll-forming wrappers. This machine comprises a guide for the winding mandrel which is movable on guiding rails and in parallel with respect to a plane established by two rolls whereby guiding ledges are provided at right angles to the direction of movement (German Published Patent Application No. 24 25 454). This multiple-roll winding machine requires, however, two stationary rolls and, additionally, a movable auxiliary roll. Moreover, for carrying out movement, complicated pistons, cylinders, levers and guide rods must be provided.